Double doping of conjugated polymers with monomer molecular dopants
Double doping of conjugated polymers with monomer molecular dopants
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DOI：
10.1038/s41563-018-0263-6
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发表时间：
2019-02-01
期刊：
影响因子：
41.2
通讯作者：
Muller, Christian
中科院分区：
文献类型：
--
作者：
Kiefer, David;Kroon, Renee;Muller, Christian
分子掺杂是控制有机半导体中载流子浓度的重要手段。每个掺杂剂分子通常被认为只产生一个极化子，导致最多一个供体：受体电荷转移复合物，因此电离效率为100%。然而，由于不完全的电荷转移和未反应的掺杂剂的存在，这个理论极限很少达到。在这里，我们确定，普通的p型掺杂剂实际上可以接受两个电子每个分子从共轭聚合物具有低电离能。每个掺杂剂分子参与两个电荷转移事件，导致形成掺杂剂二价阴离子和高达200%的电离效率。此外，我们还表明，所得的整数电荷转移复合物可以以高达170%的效率解离。这里引入的双掺杂的概念可以允许优化电荷传导所需的掺杂剂分数减半。
Molecular doping is a crucial tool for controlling the charge-carrier concentration in organic semiconductors. Each dopant molecule is commonly thought to give rise to only one polaron, leading to a maximum of one donor: acceptor charge-transfer complex and hence an ionization efficiency of 100%. However, this theoretical limit is rarely achieved because of incomplete charge transfer and the presence of unreacted dopant. Here, we establish that common p-dopants can in fact accept two electrons per molecule from conjugated polymers with a low ionization energy. Each dopant molecule participates in two charge-transfer events, leading to the formation of dopant dianions and an ionization efficiency of up to 200%. Furthermore, we show that the resulting integer charge-transfer complex can dissociate with an efficiency of up to 170%. The concept of double doping introduced here may allow the dopant fraction required to optimize charge conduction to be halved.